Bitrate, sometimes written bit rate or data rate represents the number of bits processed pe unit of time. Bitrate is quantified as the bits per second or bps, usual in a conjunction with a metric prefix (kilo, mega, giga, tera). 1kilobit per second (1kbit/s) is defined as 1000 bit/s not 1024 bit/s as it is in the most of other related computer units.
In digital multimedia area, bitrate often refers to the amount of information or detail stored per unit of time of physical recording.
What is audio bitrate?
In audio and music production world, Bitrate is a term that refers to the amount of data that is used to represent an audio file. The bitrate is measured in bits per second (bps) and is directly related to the quality of the audio.
The standard for high-quality audio is the bitrate of a Compact Disc (CD) which is 1411 kbps, but other formats such as WAV and MP3 also have different bitrate range and properties to consider depending on the use case.
CD Audio Bitrate
The Compact Disc, or CD, is often used as a reference point for audio quality. CDs have a bitrate of 1,411 kbps at 16 bit, which was first established by Philips and Sony all the way back in 1980. After a few discussions on details, it was adopted as a standard in 1987. This bitrate was chosen because it allowed for a wide dynamic range and a frequency response of 20Hz to 20kHz, which is the range of human hearing. This meant that the audio on a CD would be of high quality and similar to that of a live performance.
The adoption of the CD as the standard for the sale and distribution of audio recordings rapidly replaced compact cassettes. CDs quickly became the go-to format for music lovers as they offered better sound quality, durability and convenience. The popularity of CDs reached its peak in the late 1990s, but since then the dominance of CDs has declined. The general trend has moved towards internet-based music distribution methods such as streaming services and digital downloads.
Wav Audio Bitrate
WAV (Waveform Audio File Format) is a popular audio format that is often used for music production and high-quality audio. One of the key features of WAV files is the ability to have a high bitrate, which directly impacts the audio quality. In this article, we will explore the bitrate of WAV audio and how it relates to audio quality.
WAV files that are high in quality have a bitrate that is equal to that of CDs, which is 1,411 kbps at 16 bit. This bitrate enables a broad range of volume levels and a range of sound frequencies that the human ear can detect, from 20Hz to 20kHz. This implies that the audio quality of a WAV file with this bitrate will be comparable to that of a CD. However, it is important to note that this is just one case of a WAV file and the bitrate can vary depending on the particular file.
But that isn’t the end of the story for WAV files. There are variations. The actual bitrate is determined by a specific formula which multiplies the sampling rate with the bit depth and the number of channels. This means that the bitrate of a WAV file can be higher or lower than 1,411 kbps depending on the specific file. For example, a WAV file with a 24-bit depth and a sampling rate of 96kHz would have a bitrate of 4608 kbps, which is much higher than a standard CD.
WAV files are considered to be lossless, meaning that they do not lose any audio quality during the compression process. This makes them a great option for music production and archiving high-quality audio.
When working with WAV files, it’s important to understand the bitrate and how it relates to audio quality. A higher bitrate means better audio quality but also a larger file size. If you’re working with WAV files for music production or archiving high-quality audio, a high bitrate may be preferred. However, if you’re working with WAV files for streaming or online listening, a lower bitrate may be more appropriate.
Mp3 Audio Bitrate
MP3 is a commonly used audio format that uses a compression technique to decrease the size of audio files while still maintaining as much of the original sound as feasible. The key characteristic of MP3 files is that they have a bitrate that can be variable, which affects the audio quality.
Bitrate is the product of the sample rate and the number of bits per sample used to encode the music. CD audio is recorded at a sample rate of 44100 samples per second, and the number of bits per sample also depends on the number of audio channels. CDs are stereo and have 16 bits per channel, so multiplying 44100 by 32 gives 1411200, which is the bitrate of uncompressed CD digital audio.
MP3 was designed to encode this 1411 kbit/s data at 320 kbit/s or less. As less complex passages are detected by MP3 algorithms, then lower bitrates may be employed. When using MPEG-2 instead of MPEG-1, MP3 supports only lower sampling rates (16000, 22050 or 24000 samples per second) and offers choices of bitrate as low as 8 kbit/s but no higher than 160 kbit/s. By lowering the sampling rate, MPEG-2 layer III removes all frequencies above half the new sampling rate that may have been present in the source audio.
MP3s became extremely popular in the early days of the internet due to their low file size, which made them easier to share across slow internet connections. They are still used heavily by streaming services and digital music platforms because of the balance between file size and audio quality.
When working with MP3 files, it’s important to understand the bitrate and how it relates to audio quality. A higher bitrate means better audio quality but also a larger file size. If you’re working with MP3 files for music production or archiving high-quality audio, a high bitrate may be preferred. However, if you’re working with MP3 files for streaming or online listening, a lower bitrate may be more appropriate.
Audio Bitrate on Streaming Services
The bitrate for streaming services can vary depending on the platform and the specific content being streamed. The lower bitrate will result in lower audio/video quality and a smaller file size, which is more suitable for streaming on slower internet connections, while the higher bitrate will result in higher audio/video quality and a larger file size which is more suitable for streaming on faster internet connections.
For example:
What is Audio Bitrate on Youtube?
YouTube uses a variable bitrate for its audio streaming service, which means that the audio bitrate can vary depending on the specific content being streamed and the user’s internet connection. The bitrate can range from 64 kbps to 256 kbps. The default audio bitrate for YouTube is 128 kbps, which is considered to be of good quality. However, users can upload videos with higher or lower bitrate. Additionally, YouTube also offers an option to stream in higher quality audio, such as in the YouTube Premium service, which has a bitrate of up to 256 kbps.
What is Audio Bitrate on Spotify?
Spotify uses a variable bitrate for its streaming service, which means that the bitrate can vary depending on the specific content being streamed and the user’s internet connection. The standard audio bitrate for Spotify is 128 kbps for its music streaming service, which is considered to be of resonable quality. However, Spotify also offers a higher quality streaming option at 320 kbps, which is available for users who have subscribed to Spotify Premium. Additionally, Spotify also offers an option to stream in higher quality audio, such as in the Spotify HiFi service, which has a bitrate of up to 1,411 kbps (lossless).
The quality of podcasts on all devices is roughly 96 kbps, except on the web player where it’s 128 kbps. However, if you’re using a mobile or tablet device, you have the option to lower the audio quality to low, which reduces the podcast quality to around 24 kbps.
What is Audio Bitrate on Apple Music?
Apple Music uses a variable bitrate for its streaming service, which means that the bitrate can vary depending on the specific content being streamed and the user’s internet connection.
Apple has developed its own lossless audio compression technology called Apple Lossless Audio Codec (ALAC) in addition to the standard Advanced Audio Coding (AAC) codec that is used in most streaming services. The entire Apple Music catalog is now also encoded using ALAC in resolutions ranging from 16-bit/44.1 kHz (CD Quality) up to 24-bit/192 kHz, allowing users to access music in lossless audio compression which means that it preserves all of the original data, and the difference between AAC and lossless audio is virtually indistinguishable.
What is Audio Bitrate on Soundcloud?
Soundcloud has a fixed audio bitrate of 128 kbps for its streaming service which is considered lower compared to other music streaming services, but it enables users with a limited internet connection to stream audio easily. Moreover, Soundcloud enables users to upload their own audio files with different bitrate based on the audio quality. High-quality streaming on Soundcloud is encoded in 256kbps AAC, which is equivalent to an mp3 encoded in 320kbps. Soundcloud is making efforts to make as much content as possible available for its Go+ subscribers in high-quality 256kbps AAC format.
What is Audio Bitrate on Netflix
In May of 2019, Netflix announced an increase in the bitrate for some of their audio streams. They increased the maximum bitrate for 5.1 and Dolby Atmos material from 192 kbps to 640 kbps and 764 kbps respectively. There was no information provided regarding stereo audio streams, it is assumed that they still remain at 128 kbps. While 128 kbps may not be considered high quality in terms of audio, when watching a movie or TV show, the viewer’s focus is primarily on the visual aspect and the shortcomings of audio compression may not be as noticeable. In comparison to physical media such as Blu-ray, Netflix’s audio bitrate is lower, and it is only comparable to the Dolby Digital standard used in the late 1990s.